In U.S. patent application Ser. No. 047,005, entitled "Self-Unloading Train For Bulk Commodities", a conveyor system is described that allows the rapid removal of bulk commodities from a plurality of hopper cars connected as a unit. The unit train is pulled by a conventional locomotive. Each of the hopper cars may include several hoppers having bottom discharge openings and associated gates for discharging onto an endless belt conveyor which runs the entire length of the train. A trailer car includes a transfer conveyor which receives the material from the train conveyor. As this self-unloading train moves along the straight section of track, the material may be deposited in a windrow alongside the track by the transfer conveyor. Alternatively, the unit train may be unloaded while stationary, with the transfer conveyor discharging onto a portable stacking conveyor. Other techniques are also suitable for the unloading of such a train.
In this self-unloading train, each of the hopper cars is rigidly coupled to adjacent hopper cars. This rigid coupling is required so as to maintain the proper operation and stability of the underlying conveyor system. Without rigid coupling, the conveyor belt would deteriorate rapidly because of the continual flexing between cars.
There are many other situations where the cars of a train must be rigidly coupled. Unfortunately, the rigid coupling of cars in a unit train makes it very difficult to replace the wheels of the train. In the past, this has involved a complex method of operation.
In ordinary trains, each of the cars is uncoupled from the adjacent cars and is transferred to a wheel replacement facility. At such a facility, the individual car can be jerked up, replacement wheels aligned beneath the car, and the car lowered so as to receive the replacement wheels. Since the coupling of this type of trains is a common procedure, there is no added complexity with this form of wheel replacement technique.
In rigidly coupled cars, wheel replacement presents a more difficult problem. Since each of the cars is rigidly coupled to an adjacent car, it is quite difficult to separate the rigidly coupled cars for the purpose of transferring such car to a wheel replacement facility. It is additionally difficult to "jack up" the unit train for the purpose of the wheel replacement on an individual car. A great deal of height is required for such wheel replacement. In addition, a great deal of manual manipulation is required so as to remove the present wheels and for the introduction of the replacement wheels.
It is an object of the present invention to provide a wheel pulling device that allows the wheels of a railroad car to be replaced quickly, easily, and efficiently.
It is another object of the present invention to provide a wheel pulling device that eliminate the need for the transfer of the railroad car to a wheel removal facility.
It is another object of the present invention to provide a wheel pulling device that allows wheels to be replaced at remote locations.
It is still a further object of the present invention to provide a wheel pulling device that is inexpensive to manufacture and simple to use.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.